Landslide hazard assessment triggered by rainfall in a Colombian Andes region estimating spatial, temporal and magnitude probability

Abstract

The hazard generated by rainfall-induced landslides causes a larger number of victims each year in mountainous and tropical environments, such as the Colombia Andes. The aim of this study is to generate hazard maps for rainfallinduced landslides in the Aburrá Valley, located in the north of the Colombia Andes, which is occupied by a huge number of people living in landside-prone slopes. This paper presents not just the quantitative analysis of landslide hazard with the estimation of space, temporal, and magnitude probability, but also the verification and validation of the results. In terms of the space probability, the Weight of Evidence (WoE) method was used; for the temporal probability, rainfall thresholds for landslide occurrence and their daily temporal probability were identified. Finally, for magnitude probability, the magnitude-frequency curve was used according to the multitemporal inventory of landslide elaborated. The hazard map shows that the high hazard corresponds to 75% of the landslides occurring in 37% of the study area. The medium hazard corresponds to 28% of the landslide within 56% of the study area. Lastly, the low hazard corresponds to 25% of the landslide within 7% of in the study area.